Process of preparing progressive gunpowder.



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BRUNSWICK, GERMANY PROCESS F PREPABING PROGRESSIVE GUNPOWDER.

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To all 'u1/wm. 'it man conce/rn I VBe it known t at I, Dr. Ing. WILHELM 'EBERLEIM a subject of the Duchy of Bruns wick, Empire of Germany, residing at-,77 Karlstrasse, Brunswick, Germany, havein- 4vented certain new and useful Improveinents inthe Process of Preparing Progressive Gunpowder, of which the following is a specification.

My invention relates to improvements in the process of preparing' progressive gun powder, which powder is adaptedior use in ordnance, hand fire arms, and the like.,

The explosion of ordinary gun powder in guns is so quick, that the pressure of the gases of'explosion attains ils maximum, before the projectile has begun-its movement. As is known in the art, the velocity or' the explosionV can be regulated within large limits by increasing tht` grain, or by addingthereto subst-arves such as cauiphor. How- A ever, when reducing the velocity 'by such lili means'to s'uch an 'extent that the powder is not yet completely burnt the moment the projectile begins its movement, the. unhurnt part of the powder' is not burntat all and is thrown out of the gun. -El'orts have been made to retard the explosion of the powder in such a way, that the pressure of the gases is still increasing while the projectile is in motion. For this purpose the rrrain of the Ipowder which in ordina-ry powder burns at uniform velocity from the outside to the inner parts thereof has heen composed of diifer'ent layers which burn at increasing velocity from the outside to the center of the grain. Such powders have been termed progressive powders. In such powders the outer layers do not produce more pressure than is ynecessary to start the projectile, 'so that the pressure produced by the explosion of the inner, layers has merely the function to accelerate the projectile. However the manufacture of such progressive powder is diiilcult, because so many grades of powder must he repared'and rolled one above the other as ayers are required.

The object of my improvements is to pro- Vide a process of preparing progressive powder which is more simple. and which gives a` better powder. And with this object -m View mv invention consists in pre ariug a powder in which the increase of tie veioclty of the explosion from the. outer parts Specification of Letters Patent.

Application filed December 15, 1911.

Patented May 26, 1914.

Serial No. 666,044.

continuous, for which purpose the density ot the grains -is uniformly and continuously reduced -ironi the outer parts to the center of the grains.

ln carrying my improved process into'effeet, I interrupt at the proper 1no1nentthe raporization of the gelatinating liquid, which consists :For example' of acetone, acetic ester, or ether-alcohol. The vaporization. of the said liquid begins on the s uriacc of the powder' and it slowly proceeds to the center thereoi Preferably the vaporization is accelerated hy passing warm dry air over the grains in order to cause their surfaces to harden into a -very dense mass and to permit the .liquid to escape from the inner parts only slowly. lf at the proper moment the 'vaporization is interrupted by putting the powder into another liquid. such for example as water. which is adapted to stop the.

obtained the density of which is gradually reduced toward the center.

This process is particularly advantageous in the manufacture of tube powder in which the powder when suspended in long skeins for drying, dries more rapidly at its outer surface than at its inner surface. The explosion is considerably more quick on the inner surface, than on the Outer surface, because the inner surface of the grain is also subjected to the explosion whereby the progressive action of the powder is further increased.

ln order that my invention may more clearly he understood one example of carrying the same into eii'ect is .described hereafter.

Example: Gun-cotton of a solubility of kneaded with cainplior and molded in the usual way, whereupon the. ropes of powder are uniformly dried in a current of heated air, and the vaporization of the gelatinating substance is interrupted by passing` the powder ropes into cold water, as soon as the desired difference in the density is attained. The ropes oi powder are left within the water so long that they can still he cut, whereupon they are cut and Ibrought into cold water within which they are heated to boilingr temperature. Finally the treatment is completed by drying and polishing the powder. hun similar Way iorous powders to the center of each ,grain is uniform and l for hunting, sham battles an other purposes action of the gelatinatiug liquid. a. powder iscan be treated. After the solvent b een completely evuporzrtedthe powder 1s drled, watered, again dried, and freed ofthe dust. Prior to treating the powder with substances for reducing the" temperature or 'velocity of explosion, it may be so treated as to impart thereto a density which is continuously decreased from the outer surface to the center. However, in this case 'Care must be taken, that the inner portions which are liable to absorb thel substances more readily thaii the outer, ones are not excessively enriched which would removc'their prorressiye action. Ny improved process is particularly ndu'pted for the manufacture of such powders as consist of nitro-cellulose or mixtures of nitro-cellulose. When powder of espe- -cia'lly lo`w cubic Weight (for hunting, shambattles, etc.) is to. be produced, the preliminary drymg inthe Warm air current may be omitted,

` I claim herein as :ny invention:

The hereinl described process of mak ing; u .nitro-cellulose explo'sveburning with a, rate accelerating toward the interior of the separate .pieces of the explosive, which consists in gelutinizing nitro-cellulose with a volatile solvent, forming' it into' pieces of the desired 'shape and size, vnporizing the volatile solvent until a predetermined graduated Vdensity of each piece oil'l powder, diminishing from the exterior. to the interior of the pieces, is attained and interrupting vaporization of the Volatile solvent by iin- 'inersion of the explosive in e liquid which will stopthe; action of the solvent.

In test-hunny whereof I have hereunto set my hand in presenceof two subscribing witnesses.

DR. ING. WILHELM EBERLEIN .Witnesses'z JULIUS Seaman, l/VILHELM LEHRKE.

ive cents each,l by addressing'the Commissioner of .atents, Washington, D. C. 

